Chapter 7

Theory of Household Production

Totally Revised November 15, 2009


Thus far we said an individual allocates their time between work and Leisure.  However, we know when people are home they are often performing household work.  We want to expand our model and say that people allocate their time between work and producing things in the home.  For example, child rearing and household preparation of food, cleaning etc.  Additionally the amount of labor we are willing to supply also depends on what other household members are doing.  For example, if a member of your household supplies labor and earns $150,000 per year that may influence you not to supply labor, but that does not mean you are staying home consuming leisure.  You may be spending your time raising children and managing the household.  So all household members (notice a household can be as traditional as a husband and wife or as untraditional as we like) derive joint utility from each other.  Also many commodities consumed by the household are produced or can be produced at home. Thus a household member who stays home may be engaged in production rather than just the consumption of leisure.

The new model of labor supply will examine the alternative to work at household production rather than leisure. Interestingly, the results about the supply of labor will be the same as in chapter 6.

Household time is an input in household production. Consumption of those goods produced at home provides utility.
We assume that an individual must choose between working for pay and working at home.
Assume we are talking about a single father with a child who gets satisfaction from raising his child. How much time will he spend on household work?  As before we assume there are 16 available hours to be divided between paid work, leisure, or household work. Figure 7.1
 







Time is on the horizontal axis with Household time and time at paid work. Income is on the vertical axis like before. The father wants to maximize utility and can do so by buying commodities that increase his utility (clean house, good food, happy kids, fun life) by either spending time in household production to make all these things giving him utility happen or by earning income that allows him to buy goods and services from others.

His choices are affected by his preferences, his income and his wage rate.

The indifference curve is downward sloping which represents his preferences. He wants to maximize utility for himself by allocating his time between working for pay and working at home.


Since different combinations of household time and purchased goods or services potentially generate equal satisfaction we can use indifference curves to represent all the time/good combinations that produce equal utility for the single father.  The further from the origin is the indifference curve the more utility received.
Again on any given indifference curve utility is constant.


Remember if household production increases, hours worked declines and visa versa.
What does the negative slope tell us?



What does the convexity of the indifference curve tell us?
As we spend less time in household production (moving up the vertical part) it becomes more difficult to make up for that special time with bought goods and services.  That is why the slope gets steeper; we have to pay more and more in terms of bought household goods to make up for the time not producing household goods since we are spending so little time to start off with.  Now if we are spending a lot of time on household production, to give up some of that time we do not have to hire many people.  That is, if you spend 12 hours a day on household production it is easier to spend a little less time by buying goods instead of producing them yourself. You have lots of time to give up by working.  This is why baby sitters earn very little.  You have lots of time so to get one night out you will hire a baby sitter but will not spend much.   After all, you don't need a highly trained person to care for your child on a Saturday night; you just need someone to watch them.  But if you spend very little time in household production initially then to reduce that small amount of time you spend with your child means you will need trained professional to make up for your time, thus will have to pay them  more.  Thus the slope is steeper when you spend little time in household production and flatter when you spending lots of time.  Remember if utility is constant, and there is a small amount household time to begin with, a further reduction may be hard to do while keeping utility constant.  Thus if the single father is traveling weeks at a time for his job (he has little time to spend with his child) he will need to pay an expensive nanny who has the training to bring up a child.  Or have the child attend an expensive boarding school as the child gets older.  On the other hand if he spends a lot of time in household production it will be easy to replace some of that time with purchased goods (the cheaper babysitter just has to watch the kid not raise him).  But as your have less time for household production your must purchase more high valued goods.
The slope shows the trade off between household time and purchased goods or services in the production of household commodities such as child rearing, or cooking or what ever is produced at home.
If the indifference curve is steep it is difficult to substitute purchased goods for the loss of an hour of household time, thus must give up a lot of purchased good.  If the indifference curve is flat then it is easier to substitute purchased goods for household time. 
                 
Notice, since there are only two uses of time (work or household production) deciding the utility maximizing mode of child-rearing is the same as deciding the utility maximizing supply of labor. 

First to maximize utility we must introduce the budget constraint line CBA. In 7.1 she earns $10 an hour and has $20 of unearned income. So her budget constraint is $180.  Just as before, the budget constraint shows different combination of purchases and household time that are possible for the individual. The slope of budget line, as before, is the wage rate.  (It tells us the increased value of purchases made possible by an additional hour of paid work) The point of tangency tells us the utility maximizing point.  This tangency point gives us the number of hours spent in household production and the value of goods bought.  Notice once the number of hours spent in household production is determined, then we know the number of hours of labor supplied.

How do we know this?



As in chapter 6 there is an income effect and a substitution effect.  We do not know which effects dominates in advance but if wages rise and the supply curve is positive then the substitution effect dominates. And if supply is negative when wages rise then the income effect dominates.
Notice if the indifference curve is steep it is more difficult to substitute purchased goods for household production.  That is it is very expensive thus you spend more time in household production and supply less labor.  If the isoquant is flatter then it is easier to substitute purchased goods for an hour of time and the utility maximizing point of tangency would show less household production and more hours worked.

If non-wage income rises for our father his budget line shifts out and he would receive more utility.  The reason he gets more utility is that he now spends more time in household production with his child (remember joint utility with child) and supplies less labor. Thus we see the income effect.  Notice exact same income effect as in chapter six.  When income rises he spends more time in household production with his child and thus works less hours.  (In chapter 6 when income rose he bought more leisure and worked fewer hours) 

While the income effect tells us the father will spend less time in the paid labor market the substitution effect tells us he will spend less time in household production (because cost more when wages rise) thus he will work more hours.
Thus even though this model emphasizes household production rather than leisure, the conclusion is the same about how much labor we supply.  This model does however give us a deeper understanding about how an individual determines how much labor they will supply in the paid labor market.

Tripartite Choice, Market work, household work, leisure

Our model is now expanded in that now we can take into consideration three ways in which people spend their time.  Market work (earning income) household work and leisure activities.

Chapter 6 indicated that the substitution effect tends to dominate for women.  Thus when their wages rise they tend to supply more labor and buy less leisure.   One reason for this is that for women in the early 1960’s and 1970’s they had low labor force participation rates and thus spent a lot of time not in the paid labor market.  Usually they didn't just consume leisure but spent time in household production. When their labor force participation rates started to rise they had less time in non paid hours including household production thus they had less time to give up when wages increased. Consequently we start to see a supply curve for labor that resembles males.

Men on the other hand tend to have the income effect dominate.  Since they spend very little time in household production to start off with  when their wages increased the income effect tended to dominate, i.e. wages went up they worked less because they bought more leisure.
The difference between men and women with respect to the substitution effect can also be explained by the following.
Since their is a substitution effect for household production and leisure we note that men for reasons of traditional and social and cultural mores tend not to partake much in household production.  Men traditionally worked and did not stay at home.  This work experience raises their productivity for working thus allowing them to command a greater income.  Men specialized in working in the paid labor market.

Women by tradition tended to participate in household production.  They were relatively more productive than men because historically they provided these tasks.  If they were so productive at home they did not have the skills to earn a higher wage in the paid labor market.  Thus their time especially when young children were around was worth more in household production than in the paid labor market.  As social conditions changed and more women entered the labor market they became more productive and earned more income.  Government also made it illegal to discriminate against women.  We notice that when wages rise for women the substitution effect between market and household-work is stronger than men. Thus when wages rise women tend to substitute goods for hours spent in household production.  Thus they spend less time in household work and supply more labor when wages rise.  (Substitute work for household production)  Also as wages rise women buy less leisure because it is more expensive and work more hours.  Thus we see for females there are two substitution effects which have them working more hours when wages rise. 
  
 Men on the other hand do not provide as much household production so when their wages rise they have the substitution effect for leisure but not for household production.  So they have a bigger income effect and as wages rise for men they work less.  Women on the other hand have two substitution effects thus when wages rise they tend to work more to make up for household production which they now purchase. 
  Now as women’s LFPR increase they have less time to give up in household production thus they work more hours and start converging to men in hours worked.

Joint decision to supply labor

The decision to supply ones own labor is jointly determined by what other members of the household are doing.  Their is a joint decisions that affect the labor supply.
Partners tend to specialize between household and market work.  How do partners determine who specializes in what.  Who will be the primary care giver of children is often a major joint labor decision.  This will depend on who is relatively more productive at home and who is more productive at work.  Who is more productive at home depends upon who can produce more commodities (hence more utility) at home.  Who’s is more productive at work depends upon who can generate more income which will allow them to buy more goods for every extra hour worked.

Who stays at home depends on how much you forfeit in pay, and how productive you are at child rearing.  As we just mentioned females traditionally do child rearing due to socialization, thus females tend to be more productive in household production than men.  Since they do not have the market experience nor the training females earn less than men. Thus their opportunity cost are lower.  Consequently they specialized in household production and child rearing.  However, as wages change for women they must forfeit more and more goods to stay home, thus they will spend less time in child rearing. (there opportunity costs are rising)  As more women work and gain experience and become more productive in the paid labor market they earn more.  While they are working men are doing more child rearing and becoming more productive at household production (more experience makes you more productive).  Thus the shift of specialization is starting to change.  If partners are substitutes for each other in household production if one increases labor supply the other will decrease labor supply.  If on the other hand the two are complements in the consumption of household goods, then if one increases supply of labor the other will do the same.  Theory can not predict if people are substitutes or complements in household production. 

Discouraged and Added worker hypothesis

Suppose males work in the paid labor market and females engages in household production.  Also suppose there is a recession and the male becomes unemployed.  His market productivity declines relative to his household productivity (which does not decline at all as a result of the recession.)  Thus the family may benefit by him engaging in household production.  In order for the family to maintain same utility the spouse of the unemployed partner may enter the labor market to generate income to offset what the unemployed partner is loosing.  Thus the husband stays home and engages in household production.  Thus during a recession a worker is added to the labor market.  This was very valid when LFPR rates were low for women.  But now since LFPR are higher not sure if it is as valid.  This is like an income effect because as income falls more people in the family seek market work.  If seeking market work less time is spent in consumption as income declines, thus an income effect.  Sometimes when women become an added workers and do not get a job the unemployment rate gets even higher because now two people are out of work because the added worker could not find a job.

There is also what is called a discouraged worker effect.
As wages fall due to unemployment the husband gets discouraged and stops looking for work.  This is usually after a long period of not finding a job.  Basically people feel that it is a waste of time looking for work, and it would be better for them to spend time in household production.  Thus because of high unemployment during a recession, real wages decline and a person expected wage fall thus give up looking for work.  Supply of labor declines and hours in household production increases.  This is the substitution effect.  (Notice opposite of the substitution effect when we discussed it for wages rising) now wages are falling.
Thus the substitution effect of the discouraged worker offsets the income effect of the added worker.  Which one is stronger is an empirical question.  The added worker effect tends to be small.  The discouraged worker effect tends to dominate.  This leads to hidden unemployment, because when out of the labor force no longer considered unemployed.  Hidden unemployment can boost unemployment by as much at 2%.

Life-Cycle Aspects of Labor Supply

People will vary the amount of labor they supply over different points of time in their life cycle.  Thus we can add another dimension to the supply of labor by looking at how LFPR differ at different points in a person’s life-cycle.  For example 18 year olds have a low opportunity cost so it pays for them to get an education and not be in the labor force.  When a family has young children one member of the family might be relatively more productive in household production thus will not supply labor.  Since their indifference curve is steep (showing they would need a lot of money to make up for reduced time in household production) they tend to spend more time in household production.  Since this is often the mother we see mothers of young children spend more time in household production than in the paid labor market.

Also as we age we often slow down and become less productive in the paid labor market, thus it may pay for us to retire because our opportunity costs are being reduced. 
Thus we see that the supply of labor varies as we enter and exit different stages in our lives.